69 research outputs found

    To what extent is behaviour a problem in English schools?:Exploring the scale and prevalence of deficits in classroom climate

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    The working atmosphere in the classroom is an important variable in the process of education in schools, with several studies suggesting that classroom climate is an important influence on pupil attainment. There are wide differences in the extent to which classroom climate is considered to be a problem in English schools. Some ‘official’ reports suggest that behaviour in schools is ‘satisfactory or better’ in the vast majority of schools; other sources have pointed to behaviour being a serious and widespread problem. The paper details four studies conducted over the past decade which aimed to explore these disparities. The aim of the research was to gain a more accurate insight into the extent to which deficits in classroom climate limit educational attainment and equality of educational opportunity in English schools. The findings question the suggestion that behaviour is satisfactory or better in 99.7% of English schools and the concluding section suggests ways in which deficits in classroom climate might be addressed. Although the study is limited to classrooms in England, OECD studies suggest that deficits in the working atmosphere in classrooms occur in many countries. The study therefore has potential relevance for education systems in other countries

    Influence of Halogen Bonding Interactions in Crystalline Networks of Tetraarylethylene Halobenzoyl Esters

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    Solid state halogen bonding interactions have been examined in structurally similar tetratopic haloarenes bearing a common tetraphenylethylene core. This study was designed with the aim of providing insight into the relative importance of fundamental solid state halogen bonding interactions (i.e., halogen···halogen, halogen···π, and halogen···carbonyl) in systems devoid of strong hydrogen bonding groups. The substrates used in this study all featured four halobenzoate substituents (halogen = Br or I) attached to the four para positions of tetraphenylethylene with conformationally flexible ester linkages. A total of nine crystal structures from five different tetraarylethylene substrates were obtained. While distinct and unique X···O and X···π halogen bonding interactions were identified in each structure, all structures displayed nominally similar packing arrangements generally consisting of one-dimensional ribbons aligned to generate non-interpenetrating two-dimensional sheets. This feature may be a consequence of extensive edge-to-face arene–arene interactions found in each structure and may indicate a greater structure-determining role for aryl-H···π interactions relative to halogen bonding contacts in this system

    Charge-Assisted Halogen Bonding in Bromo- and Iodophenylpyridinium Chlorides

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    Ten <i>N</i>-halophenylpyridinium salts (halogen = Br or I) with chloride (and in one case iodide) counterions have been prepared and structurally characterized in order to examine the degree of solid state halogen bonding exhibited in these systems. N-Halophenylpyridinium salts are easily synthesized from existing pyridines, and the cationic pyridinium group is expected to increase the halogen bond donor ability of attached halophenyl moieties. Halide anions functioning as halogen bond acceptors facilitate formation of charge-assisted halogen bonds. All five substrates featuring iodophenyl or diiodophenyl substituents displayed the expected halogen bonding interactions. In several cases halide ion acceptors were also engaged in complementary hydrogen bonding interactions with C–H groups of pyridinium rings and O–H groups of water solvates. Halogen bond donors containing a diiodophenyl group formed either an extended network or discrete supramolecular macrocyclic constructs through ArI···Cl<sup>–</sup>···IAr bridging interactions. Significantly fewer and weaker halogen bonding interactions were observed in crystals of <i>N</i>-bromophenylpyridinium salts. The attenuation of halogen bonding in these substrates is attributed to the inability of the activated bromoarene halogen bond donors to compete with hydrogen bond donors (C–H/O–H residues) for the halide anion
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